VANCOUVER -- The novel coronavirus might have reached Canada weeks before the first official case was diagnosed in late January of 2020, says an expert who tracks pandemics.

Prof. Sarah Otto of the University of British Columbia said it is possible there were infections of COVID-19 a month or two before the first official case.

A traveller could have returned to Canada and was just getting over the illness or was sick and didn't go out while they were infectious, she said.

Reconstructing early travel patterns of those carrying COVID-19 around the world might lead to better policies before pandemics take hold, said Otto, who is an expert on the mathematical models of pandemic growth and control in the university's zoology department.

"I don't think that we had any cases that then sparked community spread," she said.

Researchers have developed a phylogenetic or family tree of the COVID-19 strains from around the world to determine when the virus was in the community, she said. They analyzed over 700,000 sequences of its genome from positive cases since it was first found in Wuhan, China, in late 2019.

"If you trace this family tree, you can go back to the ancestor and figure out when it first arrived in humans," she said in a recent interview.

"And that family tree kind of funnels together into one place in time, and that is around the end of 2019."

Otto's findings are in keeping with a United States study published in the journal Clinical Infectious Diseases in November, which found the virus was in that country as early as December 2019, although community transmission of COVID-19 didn't begin until February.

The first media reports about the virus in Wuhan were on Dec. 31 when Chinese experts investigated an outbreak of a respiratory illness after 27 people fell ill.

Dr. Ronald St. John, the former head of the federal Centre for Emergency Preparedness, said that was also the day when Canada was first warned of the disease through the Global Public Health Intelligence Network, an early warning system for public health threats worldwide.

Experts say Canada missed an opportunity to better control the spread of COVID-19 by limiting the flow of people across the border sooner and analyzing outbreaks to alert the public.

St. John said the government was trying to strike the right balance between anticipating the problem and finding solutions. Suggesting the closing of airports and the border with the United States might not have been welcomed, he added.

"Politicians would probably think you would have lost your mind."

Wesley Wark said the federal government didn't appreciate how quickly the virus could spread from China to the rest of the world.

Initially, the federal government's view of the virus was "rooted in optimistic hope" that COVID-19 would not be as infectious as it turned out to be, said Wark, an adjunct professor at the University of Ottawa who specializes in international affairs and intelligence gathering.

"In retrospect, that idea is baffling," he said.

"But it was the official wisdom that was contained in the risk assessments that were produced by the Public Health Agency of Canada. And that was a terrible failure of assessment, of judgment."

Other missteps include allowing travel, confusing messages on physical distancing, hygiene, wearing masks and not acquiring enough personal protective equipment, he said.

"We believed, somehow, that Canada was going to be safe from the kind of global march of this virus," Wark said.

"We put too much faith in the preparedness of our health system to meet it. We just overlooked so many things. And at the end of the day, if there is any explanation for this it is a combination of hubris that Canada would pull through this and failure of imagination."

The Public Health Agency of Canada said in a statement its decisions are guided by science, which is constantly "evolving" as scientists understand the virus.

"Every pandemic is different in terms of characteristics, contagiousness and how it affects people," the statement said.

The agency is working with all levels of the government, scientific and health care communities to respond to the situation, it added.

Health Canada and the Public Health Agency of Canada released "a lessons learned exercise" in September, outlining the effectiveness of their response to COVID-19 during the first seven months of the pandemic.

"It quickly became evident that the agency did not have the breadth and depth of human resources required to support an emergency response of this never-seen-before magnitude, complexity and duration," says a report by the office of audit and evaluation.

It details shortcomings in other areas including medical expertise, communications and emergency management.

In interviews, experts laid out steps they would take to improve Canada's response to emergencies and pandemics.

Julianne Piper, a researcher at Simon Fraser University in Burnaby, B.C., said early warning systems are needed so officials can assess what action is needed. There also needs to be a global public health intelligence system to ensure decision makers are aware of the warnings, she said.

"You can think of it as sort of like a smoke detector of global health, that sort of rings and says, you know, something's not quite right here, sort of be on alert, or gather more information," said Piper who studies cross-border measures adopted during COVID-19 and their affect on controlling transmission of the virus.

As part of her work, Piper said it is clear that timing matters when bringing in border measures.

Countries like New Zealand, Vietnam and Australia that had tight border restrictions as part of their early responses to COVID-19 have been more successful at curbing transmission, she said.

Stopping the virus at the gates, combined with additional domestic measures, would have "really helped slow or ideally prevent the spread of the virus," she said.

"I don't think that there's going to be a silver bullet so to speak," Piper said.

"There's not a single way to respond to a public health emergency. There are only the tools and the capacities that we know that we have to strengthen."

This report by The Canadian Press was first published March 13, 2021.